// File: foo.c

static int var;

void foo()
{
var++;
}

// end of file foo.c

// File bar.c:

static int var;

void bar()
{
var++;
}

// end of file bar.c

// file main.c

static int var;
void main()
{
foo();
bar();
printf("%d", var);
}

// end of file main.c

Question: Will the above program compile ? If so what will be the result ?

I tested the code and found it couldn't be compiled. I try to use extern in main.c to use the function foo() and bar() but it still couldn't be compiled.